Thirteen years into his NFL career after first entering the league as a fourth-round pick, Sproles has spent the better part of a decade as one of the league’s most entertaining and productive players. At 34, he ranks eighth in NFL history in all-purpose yards, and with an average season by his standards, he’ll be in the top five by season’s end. Plus, who knows? There just might be something special about this Philadelphia Eagles team.

Sproles’ longevity is notable, especially considering the nature of the position he plays. Of the 20 running backs taken in the 2005 NFL Draft, only he and Frank Gore remain in the league. Twelve of those retired running backs were drafted ahead of him. None of the 15 running backs drafted in 2006 are still playing.

Two things need to be true to make it that long in the league — you have to be really good and you have to be really good at taking care of your body. Since...